XML 34 R66.htm IDEA: XBRL DOCUMENT v3.8.0.1
Label Element Value
Risk/Return: rr_RiskReturnAbstract  
Registrant Name dei_EntityRegistrantName COLUMBIA ACORN TRUST
Prospectus Date rr_ProspectusDate May 01, 2018
Document Creation Date dei_DocumentCreationDate Apr. 30, 2018